From 33fdec139224cbcba4eeb248068d48422f31b455 Mon Sep 17 00:00:00 2001
From: Calixte Denizet <calixte.denizet@gmail.com>
Date: Thu, 20 Jul 2023 17:05:52 +0200
Subject: [PATCH] Don't replace Acroform dictionary if nothing has changed when
 saving (bug 1844572)

---
 src/core/worker.js            |  6 +++++-
 src/core/writer.js            |  2 +-
 src/core/xref.js              |  8 +++++++-
 test/pdfs/bug1844572.pdf.link |  2 ++
 test/test_manifest.json       | 23 +++++++++++++++++++++++
 5 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 test/pdfs/bug1844572.pdf.link

diff --git a/src/core/worker.js b/src/core/worker.js
index a606c74f3..04dd77e80 100644
--- a/src/core/worker.js
+++ b/src/core/worker.js
@@ -544,6 +544,7 @@ class WorkerMessageHandler {
           pdfManager.ensureCatalog("acroForm"),
           pdfManager.ensureCatalog("acroFormRef"),
           pdfManager.ensureDoc("startXRef"),
+          pdfManager.ensureDoc("linearization"),
         ];
 
         const newAnnotationsByPage = !isPureXfa
@@ -595,6 +596,7 @@ class WorkerMessageHandler {
           acroForm,
           acroFormRef,
           startXRef,
+          linearization,
           ...refs
         ]) {
           let newRefs = [];
@@ -656,7 +658,9 @@ class WorkerMessageHandler {
               infoRef: xref.trailer.getRaw("Info") || null,
               info: infoObj,
               fileIds: xref.trailer.get("ID") || null,
-              startXRef: xref.lastXRefStreamPos ?? startXRef,
+              startXRef: linearization
+                ? startXRef
+                : xref.lastXRefStreamPos ?? startXRef,
               filename,
             };
           }
diff --git a/src/core/writer.js b/src/core/writer.js
index 776d7ce35..009ea4cce 100644
--- a/src/core/writer.js
+++ b/src/core/writer.js
@@ -231,7 +231,7 @@ async function updateAcroform({
     warn("XFA - Cannot save it");
   }
 
-  if (!needAppearances && (!hasXfa || !xfaDatasetsRef)) {
+  if (!needAppearances && (!hasXfa || !xfaDatasetsRef || hasXfaDatasetsEntry)) {
     return;
   }
 
diff --git a/src/core/xref.js b/src/core/xref.js
index 1194725b8..6dfb2d770 100644
--- a/src/core/xref.js
+++ b/src/core/xref.js
@@ -33,6 +33,8 @@ import { BaseStream } from "./base_stream.js";
 import { CipherTransformFactory } from "./crypto.js";
 
 class XRef {
+  #firstXRefStmPos = null;
+
   constructor(stream, pdfManager) {
     this.stream = stream;
     this.pdfManager = pdfManager;
@@ -705,6 +707,7 @@ class XRef {
             // (possible infinite recursion)
             this._xrefStms.add(obj);
             this.startXRefQueue.push(obj);
+            this.#firstXRefStmPos ??= obj;
           }
         } else if (Number.isInteger(obj)) {
           // Parse in-stream XRef
@@ -754,7 +757,10 @@ class XRef {
   }
 
   get lastXRefStreamPos() {
-    return this._xrefStms.size > 0 ? Math.max(...this._xrefStms) : null;
+    return (
+      this.#firstXRefStmPos ??
+      (this._xrefStms.size > 0 ? Math.max(...this._xrefStms) : null)
+    );
   }
 
   getEntry(i) {
diff --git a/test/pdfs/bug1844572.pdf.link b/test/pdfs/bug1844572.pdf.link
new file mode 100644
index 000000000..ea3ed9cc8
--- /dev/null
+++ b/test/pdfs/bug1844572.pdf.link
@@ -0,0 +1,2 @@
+https://bugzilla.mozilla.org/attachment.cgi?id=9344818
+
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 32112565b..e9a9d854a 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -8008,5 +8008,28 @@
           "rotation": 0
         }
       }
+   },
+   {
+      "id": "bug1844572-save-print",
+      "file": "pdfs/bug1844572.pdf",
+      "md5": "22a96775e884131d59c05fa92e0a42f6",
+      "rounds": 1,
+      "type": "eq",
+      "link": true,
+      "save": true,
+      "print": true,
+      "annotationStorage": {
+        "pdfjs_internal_editor_0": {
+          "annotationType": 3,
+          "color": [0, 0, 0],
+          "fontSize": 10,
+          "value": "Hello World",
+          "pageIndex": 0,
+          "rect": [
+            115.80000000000001, 325.0679969482421, 171.3, 342.5679999999999
+          ],
+          "rotation": 0
+        }
+      }
    }
 ]